Dependency statement for SVG (Scalable Vector Graphics), last updated Feb 2000.


This document attemps to state the dependencies and issues between the SVG (Scalable Vector Graphics) format developed by the SVG Working Group and the WAI (Web Accessibility Initiative) PF (Protocols and Formats) Working Group.


Given that, we need to consider whether pushing to have all SVG graphic equally understandable in textual/linear format and using a keyboard only for output for instance is our best route

In a sense, SVG is 2D that we want to shrink to 1D, whereas the data used to build the SVG might already be 1D. So we should strive to get access to the real data in some cases (like for histogram chart).

Two cases worth mentioning.

Future assistive devices like haptic mice and 2D embossing/braille tablet will benefit from SVG in any case, provided structure/semantics is present (meaning a set of guidelines is present in addition to SVG); but image representation without sight is a still a research topic though (see prototypes at the Science Access Project - - at Oregon State). One of the central issues here arises from the recognition that it is often necessary to simplify a visual image significantly before it can be displayed meaningfully as a tactile graphic. Whether this process can be automated is an interesting question, as is likewise the issue of whether a graphic file format should include a means of indicating which parts of an image should be preserved when presenting it tactually.

Also, in the context of structured figures with a properly constructed auditory UA, a listener should be able to move around the components of a drawing and hear the associated meta information. A user might even be able to move through the components of the figure based on their geometric relationships. Where such navigation and controlled presentation is available, the end result in terms of how much information is conveyed to the end user is far superior to any single flat textual description of the drawing. See T. V. Raman work on AsTeR -

Usage scenario for SVG

Trying to establish a taxonomy of uses for SVG.
(I've collected a bunch of gif and jpg on the web to use as examples - on a fair use "educational" copyright usage)

Blue Sky scenario

Access is given to the rich semantics, not just to the graphical output.
Everybody has 2d access (braille matrix, screen, etc)
For graphics with no predefined semantics, proper authoring guidelines are followed that permits to reconstruct some of the semantics (2d or otherwise) in a serial medium.

First steps

Make sure SVG has enough associative and structural features to allow the definition of content guidelines that UAs can exploit to present the graphical data in a serial medium.

In particular, we started discussing what features set is important for access wrt SVG:

"Granted" features already include:

Note on connection/grouping

See message on the PF list.